Barylko S. Methodology of construction of computerized systems of control of technological parameters of textile materials

The dissertation is devoted to the decision of an actual scientific and applied problem of development of methodology of construction and practical realization of computerized systems of contactless control of technological parameters of textile materials by use of ultrasonic methods because the existing methods and tools do not allow for such operational control in the production process. The existing contact and destructive methods and means of control used to determine the technological parameters of textile materials in production are analyzed. It is shown that the actual value of technological parameters is determined by destructive and contact methods with cutting samples and weighing them, which do not allow for operational technological control in the production of canvases. The principle of operation of some measuring instruments of non-destructive testing of various parameters of textile materials is shown. It is proved that such methods and tools in general have a number of disadvantages, which are associated with the complexity of implementation, high cost, the need to adjust the components, ensuring proper operation, disposal and protection of maintenance personnel. The choice of ultrasonic methods and means of control of technological parameters of textile materials is substantiated, which, in turn, have high accuracy. The dependences of the change in the speed of propagation of ultrasonic waves in textile materials with different linear densities on their tension during the longitudinal sounding of fibers are obtained. It is proved that with increasing tension of a textile material the speed of wave propagation in it increases, and at the same tension with increasing linear density of material the speed of oscillations on the contrary decreases. The dependences of the modulus of longitudinal transmission of ultrasonic waves of a textile material on the tension and on its linear density are obtained, where for the first case the dependence increases and for the second case decreases. Dependences describing the passage of a pulsed ultrasonic signal through tissues with different phase structure, single-layer and two-layer materials with different pore sizes were obtained, which allowed to analytically determine the total thickness and basis weight of these materials. Dependences are obtained that describe the change of phase shifts of ultrasonic waves that pass through materials with different pore sizes, as well as waves that are reflected from such materials. Dependences are obtained that describe the amplitude ratios of ultrasonic waves passing through materials with different pores and the amplitude ratios of ultrasonic waves reflected from such materials, taking into account the attenuation of waves in the material itself. This allowed to show the effect of wave attenuation in materials with different structure and porosity, as well as to simplify expressions for analytical determination of technological parameters of such materials. An ultrasonic non-contact method for controlling the basis weight of fabrics, which eliminates the influence of changes in porosity and bulk density of the material on the result of the obtained parameter values has been developed. A non-contact amplitude-phase method of controlling the basis weight of woven fabrics has been developed, which should be more sensitive to the controlled parameter in comparison with the usual amplitude one. The structural scheme and the principle of operation of the computerized system of scanning of textile fiber mass and textile cloths with determination of their basis weight by phase and amplitude-phase ultrasonic methods were also developed. A non-contact amplitude-frequency method of controlling the change in the porosity of textile materials has been developed, which allows to determine an unknown parameter by changing the frequency of oscillations. Additionally, a block diagram was developed and the principle of operation of an ultrasonic computerized system for determining the change in porosity of textile fabrics was described. The proposed ultrasonic computerized system can be used to control the uneven porosity of the filter fabrics, as well as the fabric with the wrong pore size and other defects in it. An ultrasonic non-contact method of controlling the change in bulk density of textile materials has been developed, which allows to additionally take into account the influence of the tension of the fabric itself. The structural scheme and the principle of operation of the ultrasonic computerized system for determining the bulk density of textile fabrics with influence of change in the tension of the material on the process equipment during production are also developed.